Hydraulically set well packer



April 19, 1949. R, C, BAKER 2,467,801

Y HYDRAULICALLY SET WELL PACKER Fi1ed oct. 26, 1946 v 2 sheets-sheet 1 iPi l N I /Z fev/bef: I Hafer 'lm/ENTOR. V

R. C. BAKER HYDRAULICALLY SET WELL PACKER April 19, 1 949.

2 Sheets-Sheet 2 Filed Oct. 26, 1946 I INVENToR. ien/bm (I inferPatented Apr. 19, 1949 HYDRAULICALLY SET WELL PACKER Reuben C. Baker,Coalinga, Calif., assgnor to Baker Oil Tools, Inc., Vernon, Calif., acorporation of California Application October 26, 1946, Serial No.'706,001

(Cl. 16S-12) 3 Claims. 1

The present invention relates to well packers adapted to be anchored inpacked-off condition ln casings, liners, and similar conduits positionedin well bores.

Certain types of well packers embody slips which are held initially inretracted position and which are expanded outwardly into anchoringengagement with the wall of a well casing by hydraulically operatedinstrumentalities. The slips may be held rmly in retracted position byone or more shear screws that are designed to rupture at fapredetermined pressure of the fluid acting .on the hydaulic settingmechanism of the particular tool employed. Diculties are sometimesencountered, however, in achieving the tripping and setting of the slipsat the predetermined pressure. Such difculties are thought to be due toconditions in the well, including the relatively heavy viscosity of themud and similar fluids within the well casing, and sand or otherdetritus that may tend to pack and foul the setting mechanism. As aresult, it oftentimes occurs that the slips can only be set at aninordinately high pressure or the setting cannot be achieved at all uponelevation of the pressure of the fluid in the tool to a considerableextent above the predetermined value.

Accordingly, it is an object of the present invention to provide a wellpacker in which assurance is had that the slips will be tripped andreleased for movement from their` retracted position to anchoredposition against the casing by hydraulic instrumentalities atapproximately the predetermined value at which such release is to occur.

One form which the invention may assume is exemplied in the followingdescription and illustrated by way of example in the accompanyingdrawings, in which:

Fig. 1 is a longitudinal section through a well packer embodying theinvention, positioned in a Well casing with certain of its parts inretracted position.

Fig. 2 is a quarter longitudinal sectional view vsimilar to Fig. 1,disclosing the well packer partially set in the casing.

Fig. 3 is a quarter longitudinal sectional view similar to Fig. 1,illustrating the packer fully anchored in packed-off condition withinthe well casing.

Fig. 4 is a cross-section taken along the line 4-'4 on Fig. l.

As disclosed in the drawings, a well packer A is detachably secured to asetting tool l@ forming the lower end of a tubular string B running tothe top of the well bore and by means of which the packer is lowered tothe desired setting or anchoring point within the well casing C.

The packer A includes a tubular body I I having an abutment and guide I2threaded on its lower end and a head i3 at its upper end around whichthe skirt It of a cylinder is mounted. A cylinder head l5 extendsinwardly from the lower end of the skirt and carries suitable side sealrings I6 in ring grooves Il slidably engaging the external surface ofthe body I I. Suitable side seal rings I8 are also disclosed in bodyhead grooves I9 for slidable engagement with the interior of the skirtIll.

A set of upper segmented slips 2t are disposed aro-und the bodyimmediately below the cylinder head l5. These slips are held initiallyin retracted position by shear screws 2 I, attaching them to an upperconical expander 22 initially secured to the body l I by one or moreshear screws 23. The converging surfaces of the upper set of slips 2Uand upper expander 22 are so disposed with respect to one another as tosecure the packer against movement in an upward direction within thecasing C, or similar well conduit, following outward expansion of theslips 2S into engagement with the casing.

A set of lower segmental slips 2d is provided adjacent the abutment I2,and these slips are also secured by shear screws 25 to a lower taperedexpander 26 attached initially to the body II by one or more shearscrews 21. The direction of taper on the exterior of the lower expander26 and the taper on the cooperable surfaces of the lower slips 2d aresuch as to hold the well packer against movement in a downward directionfollowing expansion of the slips 24 outwardly to casing engagingposition.

A suitable lock is provided between the body I I and lower expander 26to permit upward movement of the body within this expander, but topreclude its downward movement. Such lock may be constituted by a splittapered wedge ring 28 received within the tapered groove 29in the lowerexpander 26.

A suitable packing, such as a packing sleeve 30 of rubber or similarpliant material, is disposed around the body between the upper and lowerexpanders 2l, 26. The ends of the packing sleeve 3l] are received withinannular pockets 3I formed between the expander skirts 32 and theexterior of the body II.

The setting tool I!) is threaded, as by a left-hand thread 33, into thehead I3 of the packer body. This setting tool has a lower head 34carrying suitable side seals 35 for sealing engagement with the innerwall of the body. The head 34 is disposed below body ports 36 positionedbetween the body and cylinder head seals I8, I6 to establishcommunication between the interior of the body II and the elongatedannular clearance space 31 between the body head I3 and cylinder headi5. Elongated ports 33 in the form of slots extend through the settingtool I6 between its threaded portion 33 and head 3i, establishingcommunication between the interior of the setting tool I6 and elongatedannular space 39 between the exterior of the setting tool I and theinterior of the body II.

The well packer A is run in the well bore with its parts in retractedposition, as disclosed in Fig. 1. The cylinder Ill, I is held initiallyin its upper position by one or more shear screws 46, securing the skirtI4 to the body head I3. During the lowering of the packer in the wellcasing, the tubular string B is automatically filled with the fluid inthe well casing, which flows upwardly'through the central passage 4I inthe setting tcol head 34 into the interior of the setting tool andtubular string B.

Upon reaching the point in the well casing at which the packer is to beanchored in packed-off condition, a trip fball 42 is dropped into thetubing string B and is allowed to gravitate or is pumped downwardly intoengagement with a seat 63 in the setting tool head, closing the passageIll through the head and enabling the pressure of the fluid in thetubular string B, setting tool I6, slotted ports 38, elongate annularspace 39, body ports 36 and elongate cylinder space 3'! to he .increasedto a predetermined degree suihcient to overcome the shear values of the`screws 49, 2l holding the cylinder I4, I5 in its uppermost .positionand the upper slips to the upper expander 22. Following rupture of thesescrews, the cylinder is moved downwardly to slide the upper slips 26down along the tapered surface of the upper expander 22 and outwardlyinto engagement with the casing (Fig. 2).

The shear screws 23 securing the upper expander to the body l I have agreater shear value than the cylinder screws 5I and the screws 2Iholding the upper slips 26 to the upper expander 22. The screws 21, 25holding the lower expander 26 to the body II and the lower slips 2li tothe lower expander have a. greater shear value than the screws 23extending through the upper expander 22. It is, accordingly, apparentthat only the rst two sets of screws mentioned above are first sheared,moving the upper slips 26 to anchored position against the casing.Following such anchoring, the tubular string B is pulled upwardly tofirst disrupt the screws 23 holding the upper expander 22 to the bodyII, and then move the packer body II upwardly within this upperexpander, carrying the lower expander 26 with the body toward the upperexpander 22 (which is held against upward movement by the slips 26)foreshortening the packing sleeve 30 and expanding it outwardly into rrnsealing engagement with the casing, and also firmly into engagement withthe exterior of the packer body I I. As soon as the packing structurehas been thus packed oi between the body I I and casing C, acontinuation of the upward strain on the tubular string B shears thelower expander screws 21 and lower slip screws 25, causing the abutmentI2 to move the lower slips 24 upwardly along the lower expander 26 andoutwardly into firm anchoring engagement against the casing (Fig. 3).

Following the complete setting of the upper and lower slips 26, 26, .inthe manner described, the tubular string B may be rotated to the rightto unscrew the setting tool I6 from the body head I3 at the left-handthread 33, allowing the tubular string B and setting tool I6 to beremoved from the well casing C,

The upper slips 26 prevent upward movement of the well packer and itsbody II with respect to the well casing. The lower slips 24 preventdownward movement of the well packer and its `body with respect to thewell casing, the downward moving tendency of the body being transmittedthrough the wedge lock 28, 29 to the lower expander 26, and through theslips 24 to the casing C. Thus, the well packer is prevented from movingin either longitudinal direction.

Although the screws 2| securing the upper slips 20 in retracted positionhave a predetermined shear value and are designed to rupture upon theimposition of a predetermined pressure -to `the fluid within theelongate cylinder space 3l', actual experience has demonstrated thatsometimes much higher pressures than the predetermined amounts arerequired to shear the screws, or the screws cannot be sheared at allregardless of the extent of pressure placed on the uid in the settingtool le and packer Ibody Il. It is believed that Such inability to lsetthe slips at the desired pressure is due to the plugging of parts of thetool by heavy drilling muds, sand-or other detritus that might bepresent in the well packer, acting as a solid barrier against thetransmission of iluid to the lower cylinder head I5, in order to urge itdownwardly with sumcient force againstthe upper set of slips 26. Thefluids and combinations of iuids and solid particles in the well toolmay also prevent the pressure imposed on the uid in the tubing string Band setting tool I0 frombeing transmitted through the various ports 36,.38 against the full area of the -cylinder head I5.

The present invention overcomes the above noted disadvantage of settingthe tool at much higher pressures than intended. It is to benoted thatthe setting tool itself is provided with relatively long slotted ports3B, which permits passage of uid and fluid-like materials, but preventsthe passage of large :particles as vmight tend to plug the ports 36 ofthe tool and thecylinder space 3i. It is also to be noted that arelatively long annular space 39 is provided between the ported portion38 of the setting tool and the inner wall oi the packer body I I andthat the body ports 36 are located intermediate the ends of the slottedports 38 in the setting tool and the annular space 39. Because of thisarrangement, any materials that may plug or restrict the slotted portscan do so only along part of its length, and any materials that maysettle in the annular space 69 between the setting tool and body canclose only part of such space. However, the body ports 36, themselves,will still be in full communication with the annular space 39 around thesetting tool for the purpose of receiving fluid under pressure fromwithin the setting tool, which pressure is transmitted freely through asufliciently open area of the slotted ports 38 and across a sunicientlyopen area in the annular space 39 into and through the cylinder ports36.

'11o-further preclude the effects of plugging of the hydraulic portionof the mechanism, which `may prevent transmission of the entire fluidpressure over the full area of the cylinder head'IS, the cylinder headis spaced a substantial distance below the body ports 36, the latter.exiting into .the elongate annular cylinder space 31 formedtransversely between the inner wall of the cylinder skirt I4 and anintermediate portion d5 of the body Il, which is greater in diameterthan the internal diameter of the cyl, inder head I but substantiallyless in diameter than the interna-1 diameter of the cylinder skirt. Theintermediate body head portion 45, in effect, forms a shoulder againstwhich the cylinder head l5 may abut to provide the relatively longannular cylinder space 39 .between the cylinder head I5 and body head I3when the cylinder I4, I5 is in its uppermost position. The body ports36, themselves, communicate with the elongated cylinder space 3l at itsupper end.

rlhe fluid under pressure is transmitted through `the body ports 36 andinto the cylinder space 3l. In view of the relatively large length or"this space 31, when the upper slips 2B are in retracted position, anymaterials of a solid or non-fluid transmitting nature that might bepresent in the space 3'1 can have very little, if any, effect upon thetransmission of the pressure against the full annular area of thecylinder head I5, since the ports 3E are suiiicient in number and thesolid particles that might be present in the cylinder space 3l will beinsunlcient to ll this space along its entire length. Part of theelongate space 31 might be plugged, and the fluid press-ure can still betransmitted around the plugged portion for action against the head I5.An eiective annular area around the cylinder space will still be presentto enable the Ipressure to be transmitted either through or around thesolid particles, and possibly to press the particles themselves iirmlyagainst the cylinder head I5. It is believed that the provision ofsubstantially no initial clearance space between the cylinder head andthe body head las in prior devices, permits the relatively short annularcylinder space to be plugged very readily by non-fluid materials, andpresents transmission of the fluid pressure around the full area of the,cylinder head.

Actual operation of the well packer setting tool and cylinderarrangement described in this specification has disclosed that the slips20 are tripped and set hydraulically at or near the predeterminedpressures -and values of the shear screws 2| While I have shown thepreferred form `of my invention, it is to be understood that variouschanges may be made in its construction by those skilled in the artwithout departing from the spirit of the invention as defined in .theappended claims.

Having thus ydescribed my invention, what I claim and desire to secureby Letters Patent is:

1. A Well tool, including a tubular body adapted to be positioned in awell casing, said body having a main portion and a head of a largerexternal diameter than said main portion, said body also having anintermediate shoulder between said head and main body portion having anexternal diameter which is smaller than said head diameter but grea-terthan the diameter of said main body portion, said shoulder having one ormore ports extending therethrough adjacent said head, normally retractedslips on said main body portion, an expander on said main body portionfor -eiecting movement of said slips into engagement with said casing,an annular cylinder having a skirt slidable along said head an-d1disposed over said shoulder ports, said cylinder having an annularcylinder -head slidable along said main body portion and positionedadjacent said slips and shoulder -when said slips are in retractedposition.

2. A well tool, including a tubular body adapted to be positioned in awell casing, said body having `a main `portion and a head `of a largerexternal diameter than said main portion, said body also having anintermediate shoulder between said head and main body portion having anexternal diameter which is smaller than said head diameter but greaterthan the diameter of said main body portion, said shoulder having one ormore ports extending therethrough adjacent said head, normally retractedmeans of said main body portion, means on said body for shifting saidnormally retracted means into engagement with said casing -comprising anannular cylinder having a skirt slidable along said head and disposedover .said shoulder ports, said cylinder als-o having an annularcylinder head slidable along said main body portion and positionedadjacent said normally retracted means when said normally retractedmeans is in retracted position.

3. A well tool, including a tubular body adapt-` ed to be positioned ina well casing, said body having a main portion and a hea-d of -a largerexternal diameter than said main portion, said body also having anintermediate shoulder between said hea-d and main body portion which isof a smaller external dia-meter :than said head diameter but greaterthan the diameter of said main body portion, said shoulder -having oneor more ports extending therethrough adjacent said head, normallyretracted means on said main body portion, means on said body forshifting said normally retracted means into engagement with said casingcomprising an annular cylinder having a skirt slidable along said headand dispose over said shoulder ports, said cylinder also having anannular cylinder head slidable along said -main body portion andpositioned adjacent said normally retracted means when said normallyretracted means is in retracted posi-tion, a t-ubular setting toolsecured :to said body and havving a head sealed against the inner wallof said body and disposed a substantial distance below said one -or moreports, said tubular setting tool having circumferentially spaced slotsthrough its w-all extending upwardly from said setting tool head alongand a substantial distance on both sides of said ports.

REUBEN C. BAKER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,189,703 Burt et al. Feb. 6,1940 2,228,241 Baker et al. Jan. 14, 1941

